The chemical amplification resist composition is a pattern forming material capable of forming a pattern on a substrate by producing an acid in the exposed area upon irradiation with actinic rays or radiation such as far ultraviolet light and through a reaction using this acid as the catalyst, changing the solubility in a developer between the area irradiated with actinic rays or radiation and the non-irradiated area.
In the case of using a KrF excimer laser as the exposure light source, a resin having small absorption in the region of 248 nm and having a basic skeleton of poly(hydroxystyrene) is predominantly used as the main component, and this is an excellent system capable of forming a good pattern with high sensitivity and high resolution as compared with the conventional naphthoquinonediazide/novolak resin system.
In the case of using a light source of emitting light at a shorter wavelength, for example, in using an ArF excimer laser (193 nm) as the light source, a satisfactory pattern cannot be formed even by the above-described chemical amplification system because the compound having an aromatic group substantially has large absorption in the region of 193 nm.
In order to solve this problem, a resist containing a resin having an alicyclic hydrocarbon structure has been developed for use with an ArF excimer laser.
Furthermore, it has been found that the performance can be enhanced by incorporating a surfactant into the above-described resin having an alicyclic hydrocarbon structure. For example, radial unevenness (striation) is prevented by adding a fluorine-containing surfactant to a positive photoresist composition as described in JP-A-10-307385 (the term “JP-A” as used herein means an “unexamined published Japanese patent application”).
Also, as for the basic compound which is a main constituent component of the chemical amplification-type resist composition, various compounds have been found, and photosensitive compositions containing anilines, imidazoles, pyridines or ammonia as the basic compound are disclosed, for example, in JP-A-5-127369 and JP-A-6-266111.
However, in view of integrated performance as the resist, an appropriate combination of the resin, photo-acid generator, basic compound, surfactant, solvent and the like used is actually very difficult to find out, and moreover, it is strongly demanded to satisfy both the resolution performance and the development defect performance.
Here, the development defect indicates troubles in general detected, for example, by the surface defect inspection apparatus (e.g., KLA-2360) of KLA-Tencor Corp. when the resist pattern after development is observed from right above, and examples of this trouble include post-developing scum, foam, dust, bridging between sections of the resist pattern, color unevenness and deposit. The development defect may adversely affect the formation and the like of a fine semiconductor device.